3 Answers
3

If the ripping is always happening in one spot on the floor take a really close look for any nails, tacks or even screw heads that might still be protruding. It only takes the slightest thing like this to rip the disc given that it's spinning so fast.

Carefully go over the floor either pulling the tacks out or using a punch to drive the heads of the nails a few mm below the surface.

If the floor is screwed down anywhere it will be a good idea to remove the screw, use a countersink bit on the hole and then replace the screw. Again this should be a few mm below the surface.

Another issue dyi people to not do is operate the unit correctly. There is a pin that must be removed and reinstalled to lower the upright arm into the sanding position. Any deviation on the floor can cause ripping. High boards will catch an edge as will nails, screws and tacks. This is a heavy machine and not set up for the dyi. It is a good unit but takes practice in operating such as any professional equipment. This unit weighs in at 160lbs while most dyi units should weigh in at half that. In any project preparation is key and is 99 percent of the project.

Just a guess here - but that being a rotating floor sander, my suspicion would be that they're either starting it while it's in contact with the floor or they're putting it down too fast, so that the spinning disk is pushing the sand paper against the floor while pulling it laterally at the same time.

The sander should be tilted back before starting and LIGHTLY set down on the floor.

Those rotating sanders take a LOT of practice to get good with - they're harder to control than floor buffers, and those are tricky enough W/O destroying the wood...